The subject invention relates to low-slope roofs that are typically found on commercial and industrial buildings and in particular to a prefabricated high-density polymer or predominantly polymer material cover board and a prefabricated roofing panel composite, which includes the high-density polymer or predominantly polymer material cover board and a low-density polymer or predominantly polymer material foam insulation board, for use on such low-slope roofs and to a method of making the cover board and the roofing panel composite.
Commercial and industrial buildings typically have roofs with low-slope roof decks. The roofing systems for these roofs with low-slope roof decks typically include one or more layers of a low-density roofing insulation, a layer of roofing cover boards that overlie the low-density roofing insulation layer(s), and a waterproofing membrane that overlies the layer of cover boards. The layer(s) of low-density insulation, such as a low-density polymer-based foam insulation, if not protected, can be partially crushed or otherwise damaged from worker traffic over the insulation, the placement of heaving objects on the insulation, the weather, and other causes commonly encountered in roofing construction. The layer of roofing cover boards that overlies the one or more layers of low-density insulation, protects the more fragile low density insulation from damage, acts as a fire barrier, provides a suitable substrate for the attachment of the overlying waterproofing membrane, and augments the insulating function of the low-density insulation. The uppermost waterproofing membrane layer overlying the cover board layer protects the underlying cover board and insulation layers from moisture and other adverse climatic conditions. Normally, these three components (the low-density insulation boards, the roofing cover boards, and the waterproofing membrane) of the roofing system are separately manufactured and separately and successively applied to the low-slope roof deck. While these roofing systems function very well, there has remained a need to provide an improved roofing cover board and to provide prefabricated roofing panel composites that combine at least an insulation board and the improved roofing cover board layer, and that, preferably, combine an insulation board, the improved roofing cover board layer and a waterproofing membrane. With the use of such an improved roofing cover board and prefabricated roofing panel composites, roofing systems for low-slope roof decks can be improved and/or the time, labor and costs associated with the installation of roofing systems on low-slope roof decks can be reduced. The subject invention provides an improved roofing cover board, an improved prefabricated roofing cover board and waterproofing membrane composite, an improved prefabricated roofing panel cover board and insulation board composite, and an improved prefabricated roofing panel cover board, insulation board, and waterproofing membrane composite. The subject invention also provides a method for making the improved roofing cover board and the prefabricated roofing panel composites including the improved roofing cover board that is highly productive, relatively economical, and efficient.